The Nissan 370Z (and perhaps a few other manual transmissions) have a built-in feature that automatically matches engine-revs on the downshifts so you don't have to double-clutch or heel-and-toe. Frrom what I can remember the last time I drove a 370Z, that feature can be turned off if you want to do it (or try to do it LOL) the old-fashioned way. .

 

If they space the pedals correctly, heel-toe downshifts are pretty easy, pedal placement on a Miata is perfect for this. I haven't driven a 370z(not a Nissan fan) so I can't comment, but I think there are other cars that can do this now like the Porsche 911.